6OJ1

Crystal Structure of Aspergillus fumigatus Ega3


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.76 Å
  • R-Value Free: 0.192 
  • R-Value Work: 0.162 
  • R-Value Observed: 0.163 

Starting Model: experimental
View more details

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 2.1 of the entry. See complete history


Literature

Ega3 from the fungal pathogenAspergillus fumigatusis an endo-alpha-1,4-galactosaminidase that disrupts microbial biofilms.

Bamford, N.C.Le Mauff, F.Subramanian, A.S.Yip, P.Millan, C.Zhang, Y.Zacharias, C.Forman, A.Nitz, M.Codee, J.D.C.Uson, I.Sheppard, D.C.Howell, P.L.

(2019) J Biol Chem 294: 13833-13849

  • DOI: https://doi.org/10.1074/jbc.RA119.009910
  • Primary Citation of Related Structures:  
    6OJ1, 6OJB

  • PubMed Abstract: 

    Aspergillus fumigatus is an opportunistic fungal pathogen that causes both chronic and acute invasive infections. Galactosaminogalactan (GAG) is an integral component of the A. fumigatus biofilm matrix and a key virulence factor. GAG is a heterogeneous linear α-1,4-linked exopolysaccharide of galactose and GalNAc that is partially deacetylated after secretion. A cluster of five co-expressed genes has been linked to GAG biosynthesis and modification. One gene in this cluster, ega3, is annotated as encoding a putative α-1,4-galactosaminidase belonging to glycoside hydrolase family 114 (GH114). Herein, we show that recombinant Ega3 is an active glycoside hydrolase that disrupts GAG-dependent A. fumigatus and Pel polysaccharide-dependent Pseudomonas aeruginosa biofilms at nanomolar concentrations. Using MS and functional assays, we demonstrate that Ega3 is an endo-acting α-1,4-galactosaminidase whose activity depends on the conserved acidic residues, Asp-189 and Glu-247. X-ray crystallographic structural analysis of the apo Ega3 and an Ega3-galactosamine complex, at 1.76 and 2.09 Å resolutions, revealed a modified (β/α) 8 -fold with a deep electronegative cleft, which upon ligand binding is capped to form a tunnel. Our structural analysis coupled with in silico docking studies also uncovered the molecular determinants for galactosamine specificity and substrate binding at the -2 to +1 binding subsites. The findings in this study increase the structural and mechanistic understanding of the GH114 family, which has >600 members encoded by plant and opportunistic human pathogens, as well as in industrially used bacteria and fungi.


  • Organizational Affiliation

    Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Endo alpha-1,4 polygalactosaminidase277Aspergillus fumigatus Af293Mutation(s): 0 
Gene Names: AFUA_3G07890
UniProt
Find proteins for Q4WX16 (Aspergillus fumigatus (strain ATCC MYA-4609 / CBS 101355 / FGSC A1100 / Af293))
Explore Q4WX16 
Go to UniProtKB:  Q4WX16
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ4WX16
Glycosylation
Glycosylation Sites: 5
Sequence Annotations
Expand
  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
alpha-D-mannopyranose-(1-2)-[alpha-D-mannopyranose-(1-6)]alpha-D-mannopyranose-(1-3)-[alpha-D-mannopyranose-(1-3)-alpha-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
B
8N-Glycosylation
Glycosylation Resources
GlyTouCan:  G91144YH
GlyCosmos:  G91144YH
GlyGen:  G91144YH
Entity ID: 3
MoleculeChains Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
C, D
2N-Glycosylation
Glycosylation Resources
GlyTouCan:  G42666HT
GlyCosmos:  G42666HT
GlyGen:  G42666HT
Entity ID: 4
MoleculeChains Length2D Diagram Glycosylation3D Interactions
beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
E
3N-Glycosylation
Glycosylation Resources
GlyTouCan:  G15407YE
GlyCosmos:  G15407YE
GlyGen:  G15407YE
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.76 Å
  • R-Value Free: 0.192 
  • R-Value Work: 0.162 
  • R-Value Observed: 0.163 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 44.64α = 90
b = 47.31β = 90
c = 152.51γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
XSCALEdata scaling
PDB_EXTRACTdata extraction
Arcimboldophasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Canadian Institutes of Health Research (CIHR)Canada--

Revision History  (Full details and data files)

  • Version 1.0: 2019-08-14
    Type: Initial release
  • Version 1.1: 2019-09-04
    Changes: Data collection, Database references
  • Version 1.2: 2019-09-25
    Changes: Data collection, Database references
  • Version 1.3: 2020-01-08
    Changes: Author supporting evidence
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Derived calculations, Structure summary
  • Version 2.1: 2023-10-11
    Changes: Data collection, Database references, Derived calculations, Refinement description, Structure summary